WO2025231067A1

WO2025231067A1 - Passive catheter hub release for safety iv catheter

Info

Publication number: WO2025231067A1
Application number: PCT/US2025/026978
Authority: WO
Inventors: David J. Goral; Christopher D. Roehl; George MANSOUR; Jay T. BREINDEL; Jeffrey JANOFSKY
Original assignee: ICU Medical Inc
Current assignee: ICU Medical Inc
Priority date: 2024-05-03
Filing date: 2025-04-30
Publication date: 2025-11-06
Anticipated expiration: 2026-11-03

Abstract

A catheter assembly has a septum retainer fixedly fitted in a cavity of a catheter hub. The retainer has a chamber having openings proximate to its distal end. A nose in the shape of a distally tapered cylindrical housing has two legs defining a through passageway. Respective protuberances at the distal ends of the legs are in radial alignment with the openings when the nose is inserted into the chamber. A needle having a distal bevel tip passes through the passageway to bias the protuberances into the openings to non-removably couple the nose to the septum retainer. Respective staggered cutouts at the legs accept the heel and tip portions of the bevel tip at the same time as the needle is withdrawn from the catheter hub such that the protuberances are simultaneously released from their openings to enable smooth separation of the insertion device from the catheter hub.

Description

TITLE OF THE INVENTION

PASSIVE CATHETER HUB RELEASE FOR SAFETY IV CATHETER

FIELD OF THE INVENTION

[001 ] The present invention relates to safety catheter assemblies, and more particularly to safety catheter assemblies that have a passive release feature.

BACKGROUND OF THE INVENTION

[002] Catheter assemblies are devices used for inserting a catheter into a vasculature vessel of a patient. It requires the catheter to concentrically mount about a needle with a sharp distal tip so that the catheter may be inserted into the patient along with the needle. After the catheter is placed into the vasculature for example a vein of the patient, the needle is removed from the catheter. The contaminated needle, especially its sharp distal tip, needs to be prevented from being exposed to the environment in order to protect the clinician user and other passerby from being accidentally pricked by the contaminated needle.

[003] In US patent No. 7,658,725, assigned to the same assignee as the present invention, a catheter device that uses a duck bill release mechanism is described. The disclosure of the '725 patent is incorporated by reference in its entirety to the disclosure of the present application.

[004] The release mechanism described in the ‘725 patent has two arms with a detent at the distal end of each arm. A longitudinal passageway with a constant cross dimension, or diameter, that is smaller than the cross dimension, or diameter, of the shaft of needle is formed between the two arms to enable a needle to pass through the passageway. The catheter hub has a distal end having a catheter extending distally therefrom and an open proximal end for receiving a needle inserter. An annular rib is provided about the interior wall of the catheter hub. When the duck bill release mechanism is inserted into the catheter hub, the detents would flex towards each other slightly so as to move over the rib and rest onto the distal side of the rib. Since the cross dimension of the shaft is greater than the cross dimension of the passageway, when the needle moves through the passageway, the arms are biased by the shaft of the needle in an outward or radial direction to firmly hold the detents against the distal surface of the rib. As a result, the needle inserter is fixedly coupled to the catheter hub while the shaft of the needle remains in the passageway. When the needle is fully withdrawn from the passageway, the arms of the release mechanism would return to their unbiased state as the detents are no longer being forced by the shaft of the needle to firmly pressed against the distal surface of the annular rib. But the detents remain in contact with the distal surface of the rib. To remove the inserter needle and its duck bill release mechanism from the catheter hub, the user then has to further pull on the inserter needle relative to the catheter hub with a force sufficient to dislodge the detents from the internal annular rib of the catheter hub. Due to the rigidity required for the duck bill release mechanism to be stabilized inside the catheter hub, aside from the recess cut-out at the distal portion of the arms close to the detents to provide flexibility for the detents, the arms of the release mechanism are substantially in sliding contact with the interior wall of the catheter hub. Therefore, additional withdrawal force is required to remove the needle inserter from the catheter hub. Further, for the device described in the 725 patent, the sharp distal tip of the needle has to be withdrawn into the needle guard housing. Thus, the user needs to withdraw the needle inserter a substantial distance relative to the catheter hub in order to fully withdraw the needle including its sharp distal tip into the needle guard housing before the needle inserter can be removed from the catheter hub.

[005] There is therefore a need to provide an improved catheter assembly that enables the needle inserter or needle assembly to be readily removed from the catheter hub assembly without requiring additional force to remove the needle inserter from the catheter hub when there is no longer any biased interference between the needle inserter and the catheter hub assembly. There is also a need for a catheter assembly where the removal of the needle inserter from the catheter hub does not have to wait for the entire needle to be withdrawn into the needle guard housing. There is moreover a need fora passive catheter hub release mechanism for closed catheter assemblies where the catheter hub has at least one side port.

SUMMARY OF INVENTION

[006] The present invention may be a closed system catheter assembly where a septum is positioned inside the cavity of the catheter hub to prevent fluid such as blood in the cavity from back flow. A septum retainer is secured to the cavity of the catheter hub proximal the septum for retaining the septum in place. The septum retainer has an outer wall dimensioned to mate with the inner or interior wall at a proximal portion of the cavity of the catheter hub. The septum retainer has a chamber defined between a distal end that includes an aperture and an open proximal end that may be flush with the open proximal end of the catheter hub when the septum retainer is inserted into the catheter hub. Opposing openings or recesses are provided proximate the apertured distal end of the septum retainer. At least one annular ridge or rib is provided at the outer wall of the septum retainer to locking ly couple with a counterpart annular groove formed at the interior wall of the catheter hub so that the septum retainer is fixedly coupled to the catheter hub. Another embodiment of the invention may have the annular groove at the outer wall of the septum retainer and the counterpart annular rib at the inner wall of the catheter hub for fixedly coupling the septum retainer to the catheter hub.

[007] The needle inserter device or insertion assembly of the present invention has a nose structure, or nose portion or simply nose, attached to a needle guard housing. A needle cannula, or simply needle, with a sharp distal tip has a proximal end attached to a needle hub positioned inside a through bore or channel of the needle guard housing. The needle hub is slidably movable along the channel relative to the needle guard housing. The nose of the insertion assembly may have at least two arms or legs that form a frustoconical or cylindrical housing that tapers distally toward the distal end of the nose. A protuberance at the distal end of each of the legs protrudes in an outward or radial direction towards the wall of the septum retainer. The protuberance may be a protrusion, bump, detent or some other known extensions integrally provided at the distal end of each of the legs. [008] The distal portion of the nose fits to the proximal portion of the chamber of the septum retainer. As the legs of the nose taper distally toward each other, a passageway that has a distally tapered cross dimension or diameter extends along most of the cylindrical housing until the passageway reaches a distal section of the nose. The cross dimension of the passageway at the distal section of the nose remains constant and is slightly smaller than the cross dimension of the needle while the distally tapered portion of the passageway has a distally decreasing cross dimension that remains larger than the diameter of the shaft of the needle therealong. Thus, when the needle moves through the distal section of the passageway, the legs at the distal section are biased outwardly by the shaft of the needle toward the inner wall of the septum retainer and the protuberances or protrusions at the distal ends of the legs enter into their corresponding openings proximate to the apertured distal end of the septum retainer to provide an interference fit between the septum retainer and the nose. As long as the shaft of needle continues to bias the distal section of the legs radially, the protrusions or protuberances at the distal ends of the legs are forced into their respective openings to fixedly couple the septum retainer and the nose together, and therefore prevent the catheter hub and the insertion assembly from separating.

[009] When withdrawn from the catheter, the needle is moved proximally relative to the catheter hub through the catheter hub cavity and past the septum into the nose. When the distal tip of the needle is withdrawn past the distal section of the passageway into a conical bore that separates the distal section from the tapered passageway of the nose, since the distal section is no longer biased by the needle, the legs would return to the unbiased state and the protuberances at the distal ends of the legs retract from the openings at the septum retainer so that the interference hold between the protuberances at the nose and the openings of the septum retainer is removed. And since the cross dimension of the protuberances of the nose is smaller and at most substantially the same as the diameter of the chamber of the septum retainer, the needle inserter can readily be removed from the catheter hub without additional pulling force, and with the distal tip of the needle housed in the conical bore of the nose. [0010] The passively smooth removal of the nose from the septum retainer therefore enables the needle inserter assembly to be readily removed from the catheter hub assembly. The passively smooth removal may also be contributed by the tapered legs of the nose not being in contact, or at most be in slidably movable contact, with the interior wall of the septum retainer.

[0011] Counterpart lock mechanisms provided at the needle hub and the needle guard housing interlock to prevent the distal tip of the needle from moving distally once the distal tip of the needle is inside the conical bore of the nose. The distal tip of the contaminated needle is thus prevented from being exposed to the environment. The lock mechanism at the needle guard housing may be provided at the proximal end portion of the housing to interlock with the lock mechanism at the needle hub if the needle is to be fully withdrawn into the needle guard housing to be stored in the needle guard housing.

[0012] To prevent the protuberances at the two legs from being not fully released from the opposing openings when the needle is being withdrawn from the septum retainer in the catheter hub, taking notice that the distal tip of the needle has a sharp beveled tip having an axial length and that the bevel tip slopes or angles downwardly from its bevel heel to its bevel tip, respective cutouts may be formed or configured at the opposing surfaces of the two legs that define the passageway of the nose. These opposing, or inside, surfaces of the two legs may be in biasing contact with the opposite surfaces of the needle that have the bevel heel and the bevel tip. For the inside surface of the one leg that comes into contact with the surface of the needle that has the bevel heel, the cutout thereat is configured in the shape of the bevel heel such that the bevel heel portion of the needle will fit into the cutout when the heel of the beveled tip of the needle reaches that cutout. Similarly, the cutout at the surface of the other leg that comes into contact with the surface of the needle that has the bevel tip is configured in the shape of the bevel tip so that bevel tip of the needle would fit into that cutout when the bevel tip reaches it. The cutouts for the bevel heel and the bevel tip of the needle may be refereed to as the bevel heel cutout and the bevel tip cutout, respectively. [0013] The bevel heel and bevel tip cutouts are configured such that their respective distal ends are separated by an axial length that corresponds to the axial length of the beveled distal tip of the needle to provide staggered release points for the nose inside the septum retainer. Putting it differently, when the needle is being withdrawn proximally relative to the catheter hub, the two legs that define the nose will continue to be biased radially by the shaft of the needle to maintain coupled contact with the septum retainer after the distal tip of the needle first enters the nose to ensure that the radial orientation of the protrusions with the cutouts at the nose be maintained so that there is no partial release or snagging of the nose within the septum retainer. It is only when both the bevel heel and the bevel tip of the needle reach their respective cutouts and are received therein as the needle continues to be withdrawn proximally relative to the catheter hub, would the legs be no longer biased radially by the shaft of the needle. As the bevel heel and bevel tip cutouts are staggered axially along the respective opposing surfaces corresponding to the axial length of the bevel distal tip portion of the needle, the bevel heel and the bevel tip would be received by their respective cutouts at the same time as the needle is being withdrawn proximally so that the protuberances are released simultaneously from their openings at the septum retainer. With the protuberances retracted simultaneously from their openings, there is no partial release or snagging of the nose within the septum retainer such that the insertion assembly may be removed from the catheter hub in a passively smooth manner.

[0014] The present invention is therefore directed to a catheter assembly, comprising: a catheter hub having a body defining a cavity between a distal end and a proximal end, a catheter having a distal end extending from the distal end of the catheter hub; a septum fixedly positioned in the cavity proximal of the distal end of the catheter hub; a septum retainer positioned in the cavity of the catheter hub proximal to the septum and fixedly attached to the catheter hub, the septum retainer having a chamber defined by a wall extending between an apertured distal end and an open proximal base, two opposing openings configured in the wall of the septum retainer proximal to the apertured distal end; an insertion device having a nose configured as a cylindrical housing adapted to be inserted into the chamber of the septum retainer, the cylindrical housing extending from an annular base having a dimension configured to matingly fit into the chamber from the open proximal end of the septum retainer, the cylindrical housing defining a passageway and having two legs each including a distal end having a protuberance that extends radially toward the wall of the septum retainer, the protuberances freely movable along the wall of the chamber when in an unbiased state; a needle of the insertion device having a shaft with a distal tip movable through the passageway of the nose, the shaft adapted to pass between the legs and through the apertured distal end of the nose to pierce through the septum and to slidably move along the catheter; wherein when the distal tip of the needle is positioned distal of the protuberances, the protuberances are biased by the shaft of the needle into corresponding ones of the openings at the septum retainer such that the nose and the septum retainer are non- removably coupled to each other; and wherein when the distal tip of the needle is positioned proximal of the protuberances, the protuberances are in the unbiased state away from the openings at the wall of the septum retainer such that the insertion device is removable from the catheter hub with the distal tip of the needle housed inside the nose.

[0015] The present invention is further directed to a passive release catheter assembly, comprising: a catheter hub having a body including a distal end and an open proximal end, an interior wall of the body defining a cavity between the distal end and the open proximal end, a catheter having a distal end extending distally from the distal end of the catheter hub; a septum fixedly positioned in the cavity proximal of the distal end of the catheter hub; a septum retainer positioned in the cavity proximal of the septum and fixedly attached to catheter hub, the septum retainer having a wall extending between an apertured distal end and an open proximal end for defining a chamber, the wall having two openings proximal to the apertured distal end; an insertion assembly having a nose adapted to be inserted into the chamber, the nose including two legs at at least a distal section of a cylindrical housing defining a passageway through the nose, the legs having respective distal ends with corresponding protuberances facing counterpart ones of the openings at the wall of the septum retainer, the protuberances being separated by a distance defining a cross dimension that enables the protuberances to move freely along the chamber of the septum retainer when the legs are in an unbiased state; a needle having a distal tip movable between the legs through the apertured distal end of the nose, the needle adapted to pierce through the septum to slidably move along the catheter to extend the distal tip beyond the distal end of the catheter in a ready to use position; wherein in the ready to use position, the protuberances are biased by the needle passing therebetween into their counterpart openings to non-removably couple the insertion assembly to the catheter hub; and wherein the catheter assembly is in a safe position when the needle is moved proximally relative to the catheter hub to position the distal tip of the needle proximal of the protuberances.

[0016] The present invention is furthermore directed to a method of making a catheter assembly, comprising: providing a catheter hub having a body defining a cavity between a distal end and a proximal end; attaching a catheter having a distal end from the distal end of the catheter hub; fixedly positioning a septum in the cavity; fixedly attaching a septum retainer having an apertured distal end proximal of the septum to the catheter hub, the septum retainer including a wall for defining a chamber that extends from the apertured distal end to an open proximal end, two opposing openings configured in the wall proximal of the apertured distal end; configuring a nose adapted to be inserted into the chamber from a cylindrical housing having two legs each including a distal end having a protuberance that extends radially toward the wall of the septum retainer, the nose freely movable along the chamber when the protuberances are in an unbiased state; providing an insertion device including a needle having a shaft with a distal tip; configuring the needle to move along the nose such that the shaft is adapted to pass between the legs and through the apertured distal end to pierce through the septum and to slidably move along the catheter; wherein when the distal tip of the needle is positioned distal of the protuberances, the protuberances are biased by the shaft into corresponding ones of the openings at the septum retainer to prevent the nose from being removed from the septum retainer; and wherein when the distal tip of the needle is positioned proximal of the protuberances, the protuberances are not in contact with the openings at the wall of the septum retainer and the insertion device is removable from the catheter hub with the distal tip of the needle housed inside the nose.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Fig. 1 is a semi-transparent view of the catheter assembly of an embodiment of the present invention showing a needle inserter or needle inserter assembly coupled to the catheter hub in a ready to use position;

[0018] Fig. 2 is a cross-sectional view of the catheter assembly of Fig. 1 ;

[0019] Fig. 3 is a cross sectional side view of the catheter assembly shown in Fig. 2;

[0020] Fig. 4 is an illustration of the needle inserter showing the nose structure fixedly attached to a needle guard housing;

[0021] Fig. 5 Is an enlarged cross-sectional view of the nose of the needle inserter in the septum retainer of the catheter hub with the distal section of the legs of the nose being biased by the shaft of the needle in a radial direction to establish an interference hold with the septum retainer;

[0022] Fig. 6 Is an enlarged cross-sectional view of the nose of the needle inserter inside the septum retainer showing the legs at the distal section of the nose being in their natural unbiased state and the distal tip of the needle being positioned in a conical bore of the passageway;

[0023] Fig. 7 shows the needle inserter device removed from the needle hub;

[0024] Fig. 8 is an illustration of an exemplar needle guard housing with a needle hub assembly slidably movable along the channel internal of the needle guard housing;

[0025] Fig. 9 is an illustration of another exemplar nose of the needle inserter device that includes an indexing member to ensure that the protuberances at the distal ends of the legs that define the nose are in radial alignment with the opposing openings at the septum retainer;

[0026] Figs. 10A and 10B show the coupling of the nose of Fig. 9 to the catheter hub guided by the indexing member mating with a notch or receptacle at the catheter hub;

[0027] Fig. 11 illustrates a partial disengagement of the nose from the septum retainer;

[0028] Fig. 12 is a cross sectional view of a preferred embodiment of the structure of an alternate exemplar nose of the present invention;

[0029] Fig. 13 shows the axial distance between staggered release points of the nose of Fig. 12 and the relationship of the release points with the axial length of the beveled distal tip of the needle as the needle is withdrawn relative to the catheter hub; [0030] Fig. 14 shows the needle having been withdrawn proximally further within the nose to allow the needle inserter device to separate from the catheter hub and the septum retainer in the catheter hub;

[0031] Fig. 15A shows an overall view of an embodiment of the catheter assembly adapted to include the nose structure and septum retainer of Fig. 14 in a ready to use position;

[0032] Fig. 15B shows an overall view of the catheter assembly of Fig. 15A where the catheter hub assembly is separated from the needle inserter device after the needle is safely stored in the needle guard housing of the needle inserter device;

[0033] Fig. 16A shows the slot locking mechanism at the proximal end of the needle guard housing of the catheter assembly;

[0034] Fig. 16B shows the locking mechanism at the needle hub housing in locking relationship with the locking mechanism at the needle guard housing;

[0035] Fig. 17A is a perspective view showing the modification to the locking mechanism at the needle guard housing of the needle inserter assembly shown in Figs. 15A-B to provide secured locking of the distal tip of the needle further proximally into the passageway of the nose as per shown in Fig. 14;

[0036] Fig. 17B is a cross-sectional view showing the locking mechanism of the needle hub housing in locking ly relationship with the locking mechanism at the needle guard housing for fixedly holding the distal tip of the needle further proximally in the nose structure as per shown in Fig. 14;

[0037] Fig. 18 is an illustration of an exemplar nose of the needle inserter device adapted for use with needle cannulas having smaller gauges; and [0038] Fig. 19 is an alternate exemplar nose adapted to be used for needle cannulas of smaller gauges.

DETAILED DESCRIPTION OF THE INVENTION

[0039] For the description below, “distal” refers to the patient end or the end that is further away from the user of the device or component, and “proximal” refers to the non-patient end or the user end of the device or component.

[0040] With reference to Figs. 1-3, a preferred embodiment of the present invention catheter assembly with the passive catheter hub release feature is shown to include a catheter hub 2 that has a distal end 4 and an open proximal end 6. Catheter hub 2 may have at least one side port and, as shown in the figures, includes two side ports 16A and 16B. A cavity 8 is defined by the interior surface of wall 2a of catheter hub 2 to extend between distal end 4 and open proximal end 6. Respective fluid communication paths between the side ports and cavity 8 may be established between ports 14a and 14b at catheter hub 2 and the corresponding open end connectors 16a and 16b of side ports 10a and 10b. Positioned in cavity 8 proximal to ports 14a and 14b is an elastomeric self sealing member or septum 18 having a slit 18a to enable a needle 24 to pierce therethrough. When catheter hub 2 has the two side ports 10a and 10b integrally extending therefrom, one of the side ports may be used for infusing fluid into cavity 8 while the other of the side ports may be used to suction fluid from cavity 8.

[0041] Proximal of septum 18, and possibly in abutment with the proximal surface 18b of septum 18, is a septum retainer 20 that has a wall 20a that extends from an apertured distal end 20f to an open proximal end 20h (Fig. 7). A chamber 20c is defined by the interior surface of wall 20a and extends from apertured distal end 20f to open proximal end 20i of septum retainer 20. An aperture 20g is provided at the apertured distal end 28. Opposing openings 20e1 and 20e2 are provided in wall 20a of septum retainer 20 proximal to apertured distal end 20f. It should be appreciated that the term “openings” discussed herein and recited in the claims may include dents, grooves and other recesses that open to the inner wall in the chamber of the septum retainer to receive protuberances, bumps or other extensions as will be further described, infra.

[0042] Septum retainer 20 has a base 20b that has a circumferential rib 20d formed at its exterior wall that matingly couples to an annular groove 2b at the interior wall at the proximal portion of catheter hub 2. A circumferential protrusion may instead be provided at the catheter hub 2 and the annular groove may be provided to the outer wall of the septum retainer. It should be appreciated that other coacting means may be provided between the outer surface of the septum retainer and the interior surface of catheter hub to non-removably couple the septum retainer to the catheter hub such that catheter hub and septum retainer move in unison.

[0043] A needle inserter assembly or needle inserter 21 is a part of the passive catheter assembly of the present invention. As shown in Fig. 4, needle inserter assembly 21 includes a needle guard housing 22 and a nose structure or nose portion 28, which may simply be referred to as nose henceforth. Nose 28 has a base 28a fixedly attached to the distal end of needle guard housing 22 and a tapered cylindrical housing 28c formed by at least two legs 28c1 and 28c2 that tapers distally or in the distal direction from base 28a to the distal end of the legs 28c1 and 28c2. Protuberances 28d1 and 28d2 are configured at the distal ends of legs 28c1 and 20c2, respectively. As used herein, protuberance may include indents, bumps, protrusions or other conventional interfacing means at the distal end of each of the legs. Base 28a is fixedly coupled, for example by bonding, gluing or other known means and methods, to the distal end of the needle guard housing 22, such that nose 28 may be considered as a part, or an extension, of needle guard housing 22 or a needle inserter device.

[0044] Nose 28 is adapted to be inserted into septum retainer 20. Coacting indexing mechanisms for example counterpart groove/rib and rib/groove (not shown in the Figs. 1- 4), or finger extension/notch combination (Figs. 9 and 10A-10B), may be provided at nose 28 and septum retainer 20 to enable the nose and the septum retainer to be correctly aligned with each other so that the protuberances 28d1 and 28d2 at the nose are in radial alignment with openings 20e1 and 20e2 at the septum retainer after the nose is fully inserted into the chamber of the septum retainer. A push tab 22 i at the distal end of needle guard housing 22 may be used by the clinician user to push the catheter assembly in the distal direction relative to catheter hub 2 to insert the needle and the catheter concentrically overlaying the needle into the patient. The coupling of nose 28 to septum retainer 20 will be further discussed below.

[0045] As shown in Figs. 5 and 6, a passageway 30 is internal of the tapered cylindrical housing 28c along nose 28 and extends from a proximal portion 28b of base 28a to the opening between protuberances 28d1 and 28d2. The tapered portion of passageway 30 ends at a conical bore 30a which distal end merges into the narrowed distal section 30b that separates the legs 28c1 and 28c2. Distal section 30b has a constant cross dimension or diameter D3. Fig. 6 shows the sharp distal tip 24a of needle 24 being positioned in the conical bore 30a. Needle 24 has cross dimension or diameter D4. The narrowed distal section 30b extends from the distal end of conical bore 30a to the open end of legs 28c1 and 28c2. The distal opening of passageway 30 is in alignment with aperture 20g at the apertured distal end 20f of septum retainer 20.

[0046] As shown in Figs. 4-6, the cross dimension or diameter of protuberances 28d1 and 28d2 is designated D1 when legs 28c1 and 28c2 are in the unbiased state. Chamber 20c of septum retainer 20 has a cross dimension or diameter D2. As shown in Fig. 6, D1 has a slightly smaller cross dimension or diameter than D2 when legs 28c1 and 28c2 of the cylindrical housing are in the unbiased state. In the case where it is desirable to have the protuberances in slidable contact with the inner wall of chamber 20c to guide nose 20 along chamber 20c, D1 and D2 may have substantially the same cross dimension or diameter. Thus, as illustrated in Fig. 6, nose 28 and septum retainer 20 can readily be separated from each other when legs 28c1 and 28c2, and therefore protuberances 28d1 and 29d2, respectively, are in the unbiased state. This unbiased state shown in Fig. 6 may be referred to as a safe position, as the distal tip 24a of needle 24 is positioned in the conical bore 30a within nose 28, i.e., the cylindrical housing formed by legs 20c1 and 20c2.

[0047] With reference to Figs. 3 and 5, needle 24 Is shown to have moved past the apertured distal end 20f of septum retainer 20 via aperture 20g, pierced through septum 18 along slit 18a, and extended along cavity 8 of catheter hub 2 such that the shaft of needle 24 extends along the narrowed passageway 30b. As the diameter D4 of needle 24 is greater than the diameter D3 of the narrow passageway 30b, the distal sections 28c1' and 28c2' of legs 28c1 and 28c2 are biased by the shaft of needle 24 outwardly in the radial direction to move away from the longitudinal axis 32. The protuberances 28d1 and 28d2 at legs 28c1 and 28c2 in turn are biased or moved radially into opening 20e1 and 20e2, respectively, of septum retainer 20 to provide an interference coupling between nose 28 and septum retainer 20, and by extension between the insertion device 21 and catheter hub 2. In one embodiment, even though only the portions of the legs at the narrowed passageway 30b (Fig. 6) are biased outwardly by the shaft of the needle 24, the remainder portions of the legs may also move slightly in the radial direction toward the interior wall of septum retainer 20 without coming into contact with the wall, while maintaining the tapered frustoconical or cylindrical housing configuration.

[0048] At the biased state shown in Fig. 5, the outwardly biased protuberances 28D1 and 28D2 have a cross section or diameter D5. The biased state may be referred to as the ready to use position, or simply the ready position. As diameter D5 is greater than diameter D2 of chamber 20c of septum retainer 20, nose 20 is fixedly coupled to septum retainer 20, which by extension means that the catheter hub assembly and the needle inserter assembly are non-removably coupled to each other in the ready to use position. Although not shown in the figures, it should be appreciated that the distal tip 24a of the needle 24 extends beyond the distal end 9a of the catheter in the ready to use position.

[0049] In one embodiment, in the biased state or ready position, only the portions of legs 28c1 and 28c2 at the distal section 28f of the cylindrical housing are biased radially by the shaft of needle 24. The respective sections of legs 28c1 and 28c2 away from the distal section 28f remain not in contact with the interior wall of septum retainer 20 as discussed above. As a consequence, when needle 24 is retracted to the position shown in Fig. 6, with the distal tip 24a of needle 24 positioned within the conical bore 30a, as the cross dimension of protuberances 28d1 and 28d2 are returned to their unbiased state represented by diameter D1 , the needle inserter device 21 which includes needle guard housing 22 can be readily removed from septum retainer 20 without the effort or force required in the prior art catheter needle devices, for example the device described in the ‘725 patent. Moreover, in contrast to the prior art, needle 24 does not have to be fully withdrawn from the nose structure, as the user only needs to retract needle 24 until its distal tip 24a is positioned in conical bore 30a of passageway 30. The needle guard housing 22 and needle hub 26 may be configured to interlocked with each other to prevent further distal movement of distal tip 24a of needle 24 from conical bore 30a to prevent the distal tip of the needle from being re-exposed to the environment.

[0050] In operation, after use, needle 24 is withdrawn from the patient in the proximal direction relative to catheter hub 2 to remove from catheter 9. When distal tip 24a of needle 24 reaches the conical bore 30a or beyond that as per shown in Fig. 6, protuberances 28d1 and 28d2 will return to their natural position since the distal section 28f of legs 28c1 and 28c2 are no longer biased by the shaft of needle 24. Given that the cross sectional dimension D1 of the protuberances 28d1 and 28d2 are no longer in interference contact with openings 20e1 and 20e2, respectively, of septum retainer 20, and further given that D1 of the protuberances is slightly smaller or has substantially the same cross dimension as diameter D2 of chamber 20c, the needle inserter assembly 21 may be removed from the catheter hub 2 by the continuation of the same proximal motion of the user removing the needle from the patient after the catheter overlaying the needle is correctly inserted into the vasculature vessel, for example a vein, of the patient. There is therefore no additional force required for the needle assembly to be passively released from the catheter hub assembly when the needle assembly is moved by momentum proximally relative to the catheter hub. [0051] The Fig. 8 embodiment of the catheter assembly of the present invention is shown to have a needle guard housing 22 that has a through bore or channel 22a extending from its distal end 22b to its proximal end 22g. The needle hub 26 is movably mounted along channel 22c and is connected by a rib 26d that extends outside of needle guard housing 22 to connect to a finger grip portion 26b of needle hub 26. Rib 26d is slidable along a slot 22c that runs along the underside of needle guard housing 22. Finger grip portion 26b enables the user to move needle hub 26 along the length of needle guard housing 22. As needle 24 is attached to needle hub 26, proximal movement of needle hub 26 relative to needle guard housing 22 moves the needle proximally relative to catheter hub 2. The locking interaction between the needle hub and the needle guard housing is described in detail in the ‘725 patent.

[0052] Needle guard housing 22 has a lock mechanism 22h having a narrowed passage 22f configured to lockingly coupled with the lock mechanism at the rib of needle hub 26 at 22s, as described in the ‘725 patent. For the exemplar embodiment of the present inventive catheter assembly, lock mechanism 22h at the needer guard housing 22 and the lock mechanism at needle hub 26 are lockingly coupled to each other to prevent further movement of needle 24 within nose 28 once the needle tip 24a is moved into, and/or proximal of, conical bore 30a. It should be appreciated that the needle tip 24a may be positioned anywhere along passageway 30 proximal of conical bore 30a within nose 28 when the needle hub is locked in place relative to the needle guard housing.

[0053] Another embodiment of a duckbill shaped nose structure, or nose 28 that may be used with the catheter assembly discussed above to eliminate the above discussed partial engagement problem is shown in Fig. 9. The components of the Fig. 9 nose that are the same as the nose 28 discussed above are labeled the same.

[0054] As shown, nose 28 has two legs 28c1 and 28c2 with their distal protuberances or bumps 28d1 and 28d2, respectively, separated by a distance D3 that forms the passageway between legs 28c1 and 28c2. The annular base 28a’ from which the legs extend distally is structurally different from the annular base shown in Fig. 4 in that an indexing finger or member 28g extends at a right angle distally from base 28a’. Indexing member 28g mates with a bracket or notch 2c at the proximal open end of catheter hub 2 when the insertion device 21 is coupled to catheter hub 2, as per shown in Figs. 10A and 10B, to ensure that the protuberance 28d1 of leg 28c1 and protuberance 28d2 of leg 28c2 are in radial alignment with slots or openings 20e1 and 20e2, respectively, at septum retainer 20. Thus, when legs 28c1 and 28c2 are biased radially or outwardly by needle 24, protuberances 28d1 and 28d2 are moved into their corresponding openings 20e1 and 20e2. The annular base 28a’ of the Fig. 9 embodiment is fitted into an opening formed by a semi-circular flange 22i at the distal end of needle guard housing 22, as per shown in Figs. 10A-10B.

[0055] A potential problem that may arise with the duckbill nose structure discussed earlier and illustrated in Fig. 9 is the possible non-smooth removal of the insertion device from the catheter hub. This may be due to the legs of the nose not disengaging from the septum retainer at the same time thus resulting in partial disengagement or snagging of the nose in the chamber of the septum retainer when the needle inserter device is being separated from the catheter hub assembly. The partial disengagement or snagging of the nose in the septum retainer may be due to the structure of the distal tip portion of the insertion needle. Conventionally, the distal tip portion of an insertion needle is beveled such that a sharp distal tip extends downwardly at an angle from a location of the needle shaft proximal of the distal tip. The sharp beveled distal tip facilitates insertion of the needle into the patient, as the clinician user can readily see the beveled distal tip at the insertion site.

[0056] The partial dis-engagement of the legs of the nose in the septum retainer is illustrated in Fig. 11. As shown, the beveled distal tip 24a, or simply bevel tip, extends upwardly at an angle proximally to the longitudinal outer circumferential surface of needle 24 that forms the beginning of the bevel. This proximal beginning of the bevel may be referred to as the bevel heel 24b. The axial distance separating bevel heel 24b and bevel tip 24a is designated 34. [0057] In operation, as the insertion device 21 is being separated from the catheter hub 2, due to the beveled structure of the distal tip portion of needle 24, leg 28c1 of nose 28 that faces the side of needle 24 that has bevel heel 24b no longer is biased by the shaft of needle 24 when bevel heel 24b reaches and is received into the proximal cavity 28h at the proximal portion of nose 28. At the same time, leg 28c2 that faces the side of needle 24 having bevel tip 24a remains in biasing contact with the shaft of needle 24. Thus, while protuberance 28d1 is released from opening 20e1 , protuberance 28d2 remains engaged to opening 20e2. Given the partial engagement between the nose and the septum retainer, the clinician user may have difficulty in removing the needle inserter assembly from the catheter hub assembly. And even were the clinician able to withdraw the needle inserter device 21 from catheter hub 2, due to the snagging of the nose in the chamber of the septum retainer, such removal is not smooth and passive.

[0058] Fig. 12 shows a preferred embodiment of the nose structure of the needle inserter device of the present invention. The components in the Fig. 12 nose structure that are the same or similar to those in the nose structure of Fig. 9 and the earlier discussed nose structure are labeled the same. As shown, instead of the symmetrical proximal cavity 28h in the Fig. 9 nose structure, the respective opposing surfaces 28c1a and 28c2a of legs 28c1 and 28c2 are configured orformed to have non-symmetrical cutouts that are adapted to accept the bevel heel and the bevel tip portions of the needle 24. In particular, the inner surface of leg 28c1 biased by the side of needle 24 that has bevel heel 24b is configured to have a bevel heel cutout 36 having a distal end 36a while the inner surface of leg 28c2 biased by the side of needle 24 that has the bevel tip 24a is configured to have a bevel tip cutout 38 having a distal end 38a.

[0059] The bevel heel cutout distal end 36a and the bevel tip cutout distal end 38a are separated by an axial length 34', which corresponds to the axial length 34 of the beveled distal tip portion of needle 24 shown in Fig. 11. Distal ends 36a and 38b may be considered the lead-in or the release points for the bevel heel 24b and bevel tip 24a of needle 24 in that bevel heel 24b is received in bevel heel cutout 36 when bevel heel 24b reaches distal end 36a and bevel tip 24a is received in bevel tip cutout 38 when bevel tip 24a reaches distal end 38a. As shown in Fig. 13, the respective biasing engagement contacts needle 24 has with legs 28c1 and 28c2 are released when bevel heel 24b and bevel tip 24a reach and are received into bevel heel cutout 36a and bevel tip cutout 38a, respectively, as needle 24 is moved proximally relative to catheter hub 2.

[0060] By providing the staggered release points in the duckbill nose 28, the partial release condition discussed above is removed, as the axial distance 34' between the distal ends 36a and 36b, i.e . , the internal release points, is identical to the axial length 34 of the bevel of needle 24, such that legs 28c1 and 28c2 each are released from engagement with the shaft of the needle at the same time. As bevel heel 24b and bevel tip 24a are received in bevel heel cutout 36 and bevel tip cutout 38 at the same time, protrusions 28d1 and 28d2 of legs 28c1 and 28c2 are simultaneously retracted from openings 20e1 and 20e2 and return to their natural unbiased state to enable needle inserter device 21 and catheter hub 2 to be passively and smoothly separated from each other.

[0061] Fig. 14 shows the needle insertion device 21 being removed from catheter hub 2. Although not shown, catheter hub 2 remains attached to the patient with the catheter inserted into a vein of the patient. As shown, needle 24 has moved further proximally relative to nose 28 along passageway 30 such that bevel heel 24b and bevel distal tip 24a are positioned proximally away from their distal ends 36a and 38a. With no biasing thereto, legs 28c1 and 28c2 fully return to their unbiased natural state such that protuberances 28d1 and 28d2 are not in contact with wall 20a of septum retainer 20. However, it should be appreciated that in practice, due to tolerances between the components, the protuberances may actually be in a freely movable and/or slidable contact with the inner wall surface of septum retainer 20. Either way, Fig. 14 shows the scenario where nose 28 is smoothly and passively removed from septum retainer 20. As further shown in Fig. 14, needle guard housing 22 and nose 28 attached thereto are being separated from the proximal end 6 of catheter hub 2. [0062] Fig. 15A shows a preferred embodiment of a catheter assembly 40 in a ready to use position in which the needle assembly 42 and the catheter hub assembly 44 are coupled together. Fig. 15B shows the needle assembly 42 and the catheter hub assembly 44 of the catheter assembly 40 separated from each other in the safe position.

[0063] Fig. 16A shows the locking mechanism that is similar to the locking mechanism 22g shown in the Fig. 8 catheter assembly. However, the locking mechanism for catheter assembly 40 may be a substitute for the locking mechanism 22g’ at the needle protection housing 22 in Fig. 8, since the needle 24 needs only to be withdrawn proximally relative to catheter hub 2 to position the needle tip 24a in a safe position at the conical bore 30a (Fig. 8). The locking mechanism in Fig. 16A is designated 122g and the needle protection housing is designated 122.

[0064] Fig. 16B shows a needle hub assembly 126 of insertion device 21 shown in Figs. 10A-10B that includes a needle hub housing 126g. A V-shaped boss 126c of the needle hub assembly is movable along a channel 122c of needle protection housing 122 such that boss 126c is moved past a narrow slot 122f to be received in a V-shaped notch stop 122s. Similar to the needle hub assembly and the needle inserter device discussed above with reference to Fig. 8, boss 126c is connected to the needle hub grip 126b by way of rib 126a and guide 126d such that its movement is controlled by the clinician moving needle hub grip 126b. Once boss 126c moves past narrow slot 122f, it is prevented from back moving in the distal direction due to its enlarged distal end 126h. The distal tip 24a of needle 24 is thus fixedly held in nose 28 in the safe position.

[0065] To fixedly hold the distal tip of needle further proximally inside the nose structure in the preferred embodiment shown in Fig. 14, the interlocking mechanisms at the needle hub assembly 126 and the needle guard housing 122 of the catheter assembly 40 shown in Figs. 15A-15B are modified as per shown in Figs. 17A-17B. Components in Figs. 17A- 17B that are the same or similar to those in Figs. 16A-16B are labeled the same. [0066] Fig. 17A shows the locking mechanism 122g at needle protection housing 122 to have a deeper V-shaped notch stop 122s and an extended window 122w. As shown in Fig. 17B, with the deeper V-shape notch stop 122v and the wider window 122w, boss 126c is received in notch stop 122s at a distance that enables the distal tip 24a of the needle 24 to be moved further proximally inside the nose structure as shown in Fig. 14. The momentum of the clinician retracting needle hub 126b and needle hub housing 126g after the distal tip of the needle is lockingly held in the nose structure ensures the needle assembly 42 is freely and passively released from catheter assembly 44.

[0067] The nose of the inventive inserter device described above is adapted to be used with needle cannulas that are most often used, for example needles having 18, 20 and 22 gauges. There are however intravenous procedures such as for pediatrics that may require needle cannulas that have smaller diameters.

[0068] Fig. 18 shows an alternative embodiment of the inventive needle inserter adapted to be used with needles having smaller diameters, or larger gauge numbers. Components that are the same as those shown in the earlier discussed safety catheter assemblies and needle inserter are labeled with the same reference numbers. As shown, the passageway of nose 20 is formed by the slot or distance separating the two legs 28c1 and 28c2 in their unbiased state. The slot, represented by D6 in the Fig. 18 embodiment, is substantially smaller than the passageway in the earlier discussed nose structures. The smaller slot D6 between legs 28c1 and 28c2 prevents the legs from deflecting to remove protrusion 28d2 that is caught in opening 20e2.

[0069] As further shown in Fig. 18, when the needle is withdrawn from the patient, due to the clinician user conventionally having to tilt the needle upwardly at an angle away from the surface of the insertion site on the patient, a slight offset angle 0 between the distal surface 28a1 of the base 28a of nose 28 and the proximal end 6 of catheter hub 2 may result during the needle withdrawn procedure. The angle 0 in turn may cause the protuberance 28d2 of leg 28c2 to make contact with the proximal end of opening 20e2 of the septum retainer 28. As the space or cross dimension D6 between legs 28c1 and 28c2 is small, the two legs of the nose may not have as much flexibility as the nose structures in the earlier discussed embodiments. Accordingly, the clinician user may have to expand some effort to withdraw nose 20 from septum retainer 20 of catheter hub 2.

[0070] Fig. 19 shows an alternative embodiment that provides the flexibility to the legs of the nose to enable the inserter device of a small gauge needle cannula to be readily and passively removed from the catheter hub. As shown, the inner surfaces of the legs 28c1 and 28c2 facing each other are formed to have respective zigzag profiles 28c1 p and 28c2p that together form a meandering slot 46 having a space separating the legs in their unbiased state. The zigzag profiles 28c1 p and 28c2p each have respective peaks 28c1 p’, 28c2p’ and valleys 28c1p”, 28c2p". The peaks and valleys of one profile match the valleys and peaks, respectively, of the other profile such that the legs may fittingly close upon each other. Accordingly, when the legs are in their unbiased state, meandering slot 46 has a cross dimension or space that enables the legs to be flexibly moved toward each other. Thus, when needle 24' is withdrawn into the cavity or passageway 30 of nose 28 proximal of the meandering slot 46, slot 46 provides the required flexibility for the legs to come together to enable nose 28 to be readily and passively removed from catheter hub 2, even when protrusion 28d2 may be in contact with the proximal end of opening 20e2 due to offset angel 0.

[0071] With the legs in their unbiased state, the respective peaks 28c1 p’ and 28c2p’ of profiles 28c1 p and 28c2p that form meandering slot 46 effect a narrowed slot, or longitudinal through passageway, having a cross dimension D6' along the two legs 28c1 and 28c2. Thus, the nose structure shown in Fig. 19 is able to maintain the same interference with the outer diameter of the needle cannula due to its narrow slot D6', while reducing the individual leg rigidity of legs 28c1 and 28c2 so as to allow leg 28c2 to freely deflect without resistance from leg 28c1 . It should be appreciated that the zigzag profiles of Fig. 19 embodiment may also be used for the earlier discussed nose structures. [0072] It should be appreciated that the slight offset angle 0 shown in Figs. 18 and 19 may also be present at the safety catheter assemblies discussed above when the needle cannula is being withdrawn from the patient. However, since the nose structures of those earlier described embodiments were assumed to be used with needles having the commonly used gauges such as for example 18, 20 and 22, the slot D3 between the two legs of the nose of those earlier described embodiments, per shown in Figs. 4 and 9, has space sufficient to enable each of the legs to deflect freely relative to the other so that the nose, and the inserter device to which the nose is attached, can be passively separated from the catheter hub in one single continuous withdrawing motion.

[0073] It is the intension of the inventor that all matter described throughout this specification and shown in the accompanying drawings be interpreted as illustrative only and not in a limiting sense. Accordingly, it is intended that the invention be limited only by the spirit and scope of the hereto appended claims.

Claims

1 . A catheter assembly, comprising: a catheter hub having a body defining a cavity between a distal end and a proximal end, a catheter having a distal end extending from the distal end of the catheter hub; a septum positioned in the cavity proximal of the distal end of the catheter hub; a septum retainer positioned in the cavity of the catheter hub proximal to the septum and fixedly attached to the catheter hub, the septum retainer having a chamber defined by a wall extending between an apertured distal end and an open proximal base, two opposing openings configured in the wall of the septum retainer proximal to the apertured distal end; an insertion device having a nose configured as a cylindrical housing extending from an annular base and adapted to be inserted into the chamber of the septum retainer from the open proximal end of the septum retainer, the cylindrical housing having a passageway defined by two legs each including a distal end having a protuberance that extends radially toward the wall of the septum retainer, the protuberances freely movable along the wall of the chamber when in an unbiased state; a needle of the insertion device having a shaft with a distal tip movable through the passageway of the nose, the shaft adapted to pass between the legs and through the apertured distal end of the septum retainer to pierce through the septum and to slidably move along the catheter; wherein when the distal tip of the needle is positioned distal of the protuberances, the protuberances each are biased by the shaft of the needle into a corresponding opening at the septum retainer such that the nose and the septum retainer are non-removably coupled to each other; and wherein when the distal tip of the needle is positioned proximal of the protuberances, the protuberances are in the unbiased state away from the openings at the wall of the septum retainer such that the insertion device is removable from the catheter hub with the distal tip of the needle housed inside the nose.

2. The catheter assembly of claim 1 , wherein the distal tip of the needle has a beveled length extending between a proximal bevel heel and a distal bevel tip; wherein one of the two legs in biasing contact with the side of the needle having the bevel heel includes a bevel heel cutout adapted to accept the bevel heel of the needle; and wherein other of the two legs in biasing contact with the side of the needle having the bevel tip includes a bevel tip cutout adapted to accept the bevel tip of the needle.

3. The catheter assembly of claim 2, wherein the bevel heel cutout of the one leg has a distal heel end and the bevel tip cutout of the other leg has a distal tip end, the distal heel end proximal of the distal tip end by an axial distance that corresponds to the bevel length of the distal tip of the needle to provide staggered release points for the one and other legs such that, when the distal tip of the needle is withdrawn proximally into the nose, the bevel heel of the needle is received into the bevel heel cutout at the same times as the bevel tip of the needle is received into the bevel tip cutout to prevent partial release of the nose from the septum retainer.

4. The catheter assembly of claim 2, wherein the bevel heel cutout has a distal heel end and the bevel tip cutout has a distal tip end, the distal heel end and the distal tip end being separated by an axial distance that corresponds to the bevel length of the distal tip of the needle such that the one and other legs are released simultaneously from the opposing openings when the bevel heel and the bevel tip are received into the bevel heel cutout and the bevel tip cutout, respectively, as the distal end of the needle is withdrawn into the nose.

5. The catheter assembly of claim 2, further comprising an indexing member at the base of the cylindrical housing for mating with a notch at the proximal end of the catheter hub such that the cylindrical housing is guided into the chamber of the septum retainer with the one leg in biasing contact with the side of the needle having the bevel heel and the other leg in biasing contact with the side of the needle having the bevel tip.

6. The catheter assembly of claim 1 , wherein the passageway of the cylindrical housing tapers distally toward a distal section of the nose having a cross dimension smaller than the diameter of the shaft of the needle, the legs at the distal section of the nose being biased radially by the shaft of the needle to position the protuberances into the openings in the ready to use position.

7. The catheter assembly of claim 1 , wherein the base of the nose is fixedly coupled to a needle guard housing having a channel whereinto a needle hub having attached thereto a proximal end of the needle is movable relative to the needle protection housing; wherein the needle hub has a first lock mechanism and the needle guard housing has a second lock mechanism, the first and second lock mechanisms interlock to secure the distal tip of the needle in the nose when the needle hub is moved to a selected position relative to the needle guard housing.

8. The catheter assembly of claim 1 , wherein the two legs of the nose have respective surfaces facing each other that have counterpart profiles that together configure the passageway into a meandering slot having corresponding peaks and valleys when the legs are in the unbiased state, the meandering slot having a cross dimension, the counterpart profiles are adapted to come together to enable the legs to move toward each other, the peaks of the respective surfaces of the two legs effecting a longitudinal through passageway having another cross dimension that is smaller than the cross dimension of the meandering slot.

9. A catheter assembly, comprising: a catheter hub having a body including a distal end and an open proximal end, an interior wall of the body defining a cavity between the distal end and the open proximal end, a catheter having a distal end extending distally from the distal end of the catheter hub; a septum positioned in the cavity proximal of the distal end of the catheter hub; a septum retainer positioned in the cavity proximal of the septum and fixedly attached to catheter hub, the septum retainer having a wall extending between an apertured distal end and an open proximal end for defining a chamber, the wall having opposing openings proximal to the apertured distal end; an insertion assembly having a nose adapted to be inserted into the chamber, the nose including two legs defining a passageway through the nose, the two legs having respective distal ends with corresponding protuberances movable freely along the chamber of the septum retainer when the two legs are in an unbiased state; a needle having a shaft and a distal tip slidably movable between the two legs through the apertured distal end of the septum retainer, the needle piercing through the septum to extend along the catheter such that the distal tip extends beyond the distal end of the catheter in a ready to use position; wherein in the ready to use position, the protuberances are biased by the shaft of the needle into the opposing openings to non-removably couple the insertion assembly to the catheter hub; and wherein the catheter assembly is in a safe position when the distal tip of the needle is positioned in the nose proximal of the protuberances.

10. The catheter assembly of claim 9, wherein the distal tip of the needle has a beveled length extending between a proximal bevel heel and a distal bevel tip; wherein one of the two legs in biasing contact with the side of the needle having the bevel heel includes a bevel heel cutout adapted to accept the bevel heel of the needle; and wherein other of the two legs in biasing contact with the side of the needle having the bevel tip includes a bevel tip cutout adapted to accept the bevel tip of the needle.

11 . The catheter assembly of claim 10, wherein the bevel heel cutout has a distal heel end and the bevel tip cutout has a distal tip end, the distal heel end and the distal tip end being separated by an axial distance that corresponds to the bevel length of the needle such that the one and other legs are released simultaneously from the opposing openings when the bevel heel and the bevel tip are received into the bevel heel cutout and the bevel tip cutout, respectively, when the distal end of the needle is withdrawn into the nose.

12. The catheter assembly of claim 10, wherein the bevel heel cutout of the one leg has a distal heel end and the bevel tip cutout of the other leg has a distal tip end, the distal heel end proximal of the distal tip end by an axial distance that corresponds to the bevel length of the distal tip of the needle to provide staggered release points for the one and other legs such that, when the distal tip of the needle is withdrawn proximally into the nose, the bevel heel of the needle is received into the bevel heel cutout at the same times as the bevel tip of the needle is received into the bevel tip cutout to prevent partial release of the nose from the septum retainer.

13. The catheter assembly of claim 11 , further comprising an indexing member at the base of the cylindrical housing for mating with a notch at the proximal end of the catheter hub to guide the cylindrical housing into the chamber of the septum retainer with the one leg in biasing contact with the side of the needle having the bevel heel and the other leg in biasing contact with the side of the needle having the bevel tip.

14. The catheter assembly of claim 9, wherein, after the distal tip of the needle is moved proximal of the protuberances, continual proximal movement of the insertion assembly relative to the catheter hub removes the nose from the septum retainer without additional withdrawal force.

15. The catheter assembly of claim 9, wherein the two legs of the nose have respective surfaces facing each other that have counterpart zigzag profiles that together configure the passageway into a meandering slot having corresponding peaks and valleys when the legs are in the unbiased state, the meandering slot having a cross dimension, the counterpart profiles are adapted to come together to enable the legs to flex toward each other, the peaks of the respective surfaces of the two legs effecting a longitudinal through passageway having another cross dimension that is smaller than the cross dimension of the meandering slot.

16. A method of making a catheter assembly, comprising: providing a catheter hub having a body defining a cavity between a distal end and a proximal end; attaching a catheter having a distal end from the distal end of the catheter hub; positioning a septum in the cavity; fixedly attaching a septum retainer having an apertured distal end proximal of the septum to the catheter hub, the septum retainer including a wall for defining a chamber that extends from the apertured distal end to an open proximal end, two opposing openings configured in the wall proximal of the apertured distal end; configuring a nose for insertion into the chamber, the nose defined by two legs each having a distal end with a protuberance that extends radially toward the wall of the septum retainer, the nose freely movable along the chamber when the protuberances are in an unbiased state; providing an insertion device including a needle having a shaft with a distal tip; configuring the needle to move along the nose such that the shaft passes between the legs and through the apertured distal end to pierce through the septum such that the distal tip of the needle extends beyond the distal end of the catheter in a ready to use position; wherein when the distal tip of the needle is positioned distal of the protuberances, the protuberances are biased by the shaft into the openings at the septum retainer to prevent the nose from being removed from the septum retainer; and wherein when the distal tip of the needle is positioned inside the nose such that the protuberances are not biased into the openings, the nose is removable from the septum retainer.

17. The method of claim 16, wherein the distal tip of the needle has a beveled length extending between a proximal bevel heel and a distal bevel tip, the method further comprising: forming a bevel heel cutout adapted to accept the bevel heel of the needle in one of the two legs in biasing contact with the side of the needle having the bevel heel; and forming a bevel tip cutout adapted to accept the bevel tip of the needle in other of the two legs in biasing contact with the side of the needle having the bevel tip.

18. The method of claim 17, further comprising: configuring a distal heel end for the bevel heel cutout and a distal tip end for the bevel tip cutout; separating the distal heel end and the distal tip end by an axial distance that corresponds to the bevel length of the distal tip of the needle such that the one and other legs are released simultaneously from the opposing openings when the bevel heel and the bevel tip are received into the bevel heel cutout and the bevel tip cutout, respectively, as the distal end of the needle is being withdrawn into the nose.

19. The method of claim 16, further comprising: defining a passageway between respective surfaces of the two legs that face each other; forming counterpart profiles at the respective surfaces of the two legs that together configure the passageway into a meandering slot having a cross dimension defined by corresponding peaks and valleys of the profiles when the legs are in the unbiased state, the counterpart profiles are adapted to come together to enable the legs to move toward each other; configuring the peaks of the respective surfaces of the two legs to effect a longitudinal through passageway having another cross dimension that is smaller than the cross dimension of the meandering slot.

20. The method of claim 17, further comprising: providing an indexing member at the base of the cylindrical housing; providing a notch at the proximal end of the catheter hub for mating with the indexing member such that the nose is guided into the chamber of the septum retainer with the one leg in biasing contact with the side of the needle having the bevel heel and the other leg in biasing contact with the side of the needle having the bevel tip.